The use of electronic mobile devices such as cellular phones and tablet computers to play interactive games has been increasing in popularity. Some interactive games may be freely downloaded onto mobile devices from a remote server while some games require advance payment before the games may be downloaded. A variety of electronic games, initially downloadable for free, may include optional in-game content that is not free and requires a payment. Such electronic games are limited in that they only generate revenue based on in-game purchases.
Electronic games playable on mobile devices may be controlled by users via manipulation of one or more input keys and/or multiple control icons visible on the display screen of the mobile devices during game play. Some electronic games may additionally be controlled by moving, for example, tilting, the mobile device in addition to manipulating input keys and/or on-screen control icons. Some games rely on gesture recognition to control game play, e.g., golf or tennis games in which the user's simulation of a golf or tennis swing determines a virtual trajectory of a virtual ball.